diff --git a/sources/reactphysics3d/engine/DynamicEngine.cpp b/sources/reactphysics3d/engine/DynamicEngine.cpp
index 73de4e7f..20a13313 100644
--- a/sources/reactphysics3d/engine/DynamicEngine.cpp
+++ b/sources/reactphysics3d/engine/DynamicEngine.cpp
@@ -56,9 +56,9 @@ void DynamicEngine::update() {
     while(timer.getAccumulator() >= timer.getTimeStep().getValue()) {
         // For each body in the dynamic world
         for(std::vector<Body*>::const_iterator it = world.getBodyListStartIterator(); it != world.getBodyListEndIterator(); ++it) {
-            // If the body is a RigidBody
+            // If the body is a RigidBody and if the rigid body motion is enabled
             RigidBody* rigidBody = dynamic_cast<RigidBody*>(*it);
-            if (rigidBody) {
+            if (rigidBody && rigidBody->getIsMotionEnabled()) {
                 // Update the state of the rigid body
                 updateBodyState(rigidBody);
             }
@@ -70,9 +70,9 @@ void DynamicEngine::update() {
 
     // For each body in the dynamic world
     for(std::vector<Body*>::const_iterator it = world.getBodyListStartIterator(); it != world.getBodyListEndIterator(); ++it) {
-        // If the body is a RigidBody
+        // If the body is a RigidBody and if the rigid body motion is enabled
         RigidBody* rigidBody = dynamic_cast<RigidBody*>(*it);
-        if (rigidBody) {
+        if (rigidBody && rigidBody->getIsMotionEnabled()) {
             // Update the interpolation factor of the rigid body
             // This one will be used to compute the interpolated state
             rigidBody->setInterpolationFactor(timer.getInterpolationFactor());
diff --git a/sources/reactphysics3d/engine/DynamicWorld.cpp b/sources/reactphysics3d/engine/DynamicWorld.cpp
new file mode 100644
index 00000000..aec63e76
--- /dev/null
+++ b/sources/reactphysics3d/engine/DynamicWorld.cpp
@@ -0,0 +1,41 @@
+/****************************************************************************
+* Copyright (C) 2009      Daniel Chappuis                                  *
+****************************************************************************
+* This file is part of ReactPhysics3D.                                     *
+*                                                                          *
+* ReactPhysics3D is free software: you can redistribute it and/or modify   *
+* it under the terms of the GNU General Public License as published by     *
+* the Free Software Foundation, either version 3 of the License, or        *
+* (at your option) any later version.                                      *
+*                                                                          *
+* ReactPhysics3D is distributed in the hope that it will be useful,        *
+* but WITHOUT ANY WARRANTY; without even the implied warranty of           *
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the             *
+* GNU General Public License for more details.                             *
+*                                                                          *
+* You should have received a copy of the GNU General Public License        *
+* along with ReactPhysics3D. If not, see <http://www.gnu.org/licenses/>.   *
+***************************************************************************/
+
+// Libraries
+#include "DynamicWorld.h"
+
+// We want to use the ReactPhysics3D namespace
+using namespace reactphysics3d;
+
+// Constructor
+DynamicWorld::DynamicWorld(const Vector3D& gravity)
+             :PhysicsWorld(gravity) {
+
+}
+
+// Copy-constructor
+DynamicWorld::DynamicWorld(const DynamicWorld& world)
+             :PhysicsWorld(world) {
+
+}
+
+// Destructor
+DynamicWorld::~DynamicWorld() {
+
+}
diff --git a/sources/reactphysics3d/engine/DynamicWorld.h b/sources/reactphysics3d/engine/DynamicWorld.h
index b44ed1b7..a1b5df41 100644
--- a/sources/reactphysics3d/engine/DynamicWorld.h
+++ b/sources/reactphysics3d/engine/DynamicWorld.h
@@ -35,6 +35,10 @@ namespace reactphysics3d {
 */
 class DynamicWorld : public PhysicsWorld {
 
+    public :
+        DynamicWorld(const Vector3D& gravity);          // Constructor
+        DynamicWorld(const DynamicWorld& world);        // Copy-constructor
+        virtual ~DynamicWorld();                        // Destructor
 };
 
 }